VLDB 2026 Research / reviewers in the wild / expert
Nikolaos Giannakeas
dblp:80/6541
· DBLP profile ↗
26ranked-venue papers
2as first author
9since 2021 · last 2025
0000-0002-0615-783XORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Applied, interdisciplinary, general and emerging computing · 17 · 2 first-author · 5 since 2021Artificial intelligence and machine learning · 14 · 1 first-author · 6 since 2021Human-computer interaction and ubiquitous computing · 7 · 1 first-author · 3 since 2021Computer networks · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Neurodegenerative Disease Classification with EEG: A Deep Learning Approach for Dementia DiagnosisabstractAlzheimer's Disease (AD) and Frontotemporal Dementia (FTD) are two of the most common neurodegenerative disorders, most commonly leading to progressive cognitive decline. Electroencephalography (EEG) has been proven as a promising tool for early and non-invasive detection of these disorders, leveraging advanced computational methods for classification. In this study, we propose a novel Convolutional Neural Network (CNN) architecture for the automatic classification of AD and FTD using EEG-based biomarkers. Our approach utilizes Power Spectral Density derived Relative Band Power and Spectral Coherence Index as input features, extracted from preprocessed EEG signals of 88 participants following Independent Component Analysis and Artifact Subspace Reconstruction for noise reduction. The extracted features capture both spectral power variations and functional connectivity disruptions, key findings of neurodegenerative disorders. The proposed CNN model is trained and validated using a Leave-One-Subject-Out crossvalidation approach to ensure robust generalization. Experimental results demonstrate that our model achieves high classification accuracy, outperforming state-of-the-art machine learning methods and achieving competitive performance with state-of-the-art deep learning approaches. These findings highlight the effectiveness of EEG-based deep learning models for differential dementia diagnosis, providing a potential avenue for early detection and clinical decision support. Andreas Miltiadous, Konstantinos Sakkas, Emmanouil D. Oikonomou, Aimilia Ntetska, Nikolaos Giannakeas, Alexandros T. Tzallas |
CBMS | 5 |
| 2025 | Driving and Sleep Deprivation: Comparing Interventions Using a Driving Simulator with EEG AnalysisabstractThis preliminary study investigates the effects of sleep deprivation on driving performance and evaluates three gamified or stimulating interventions: airflow, music, and caffeine. Two participants completed simulator-based driving tasks in rested and sleep-deprived states. Performance was assessed via lane deviation (SDLP), and EEG data were analyzed. Sleep deprivation increased SDLP and low-frequency EEG activity, indicating reduced alertness. Caffeine showed the strongest restorative effect. Despite the small sample, results suggest EEG is useful for detecting fatigue, and gamified stimuli may support alertness during drowsy driving. Niki Eleni Ntagka, Emmanouil D. Oikonomou, Konstantinos Sakkas, Vasileios Choutas, Vasileios Aspiotis, Nikolaos Giannakeas, Alexandros T. Tzallas, Andreas Miltiadous |
CBMS | 6 |
| 2023 | A Novel Approach for Cancer Image SegmentationabstractIn this study, we present a novel approach to address the task of identifying nuclei in a diverse set of microscopy scan images containing slides from several distinct cancerous tissue types. Our approach is based on YOLOv5 algorithm. We thoroughly discuss the crucial training specifics that contributed to our outcomes. Additionally, we propose an intuitive strategy for combining multiple segmentation results to further improve the accuracy of nucleus identification. By employing this lightweight model, we successfully achieved results better or close to the state-of-the-art performance. Panagiotis N. Smyrlis, Konstantinos Vogklis, Odysseas Tsakai, Alexandros T. Tzallas, Nikolaos Giannakeas, Markos G. Tsipouras |
BIBM | 5 |
| 2023 | Deep-in-Biopsies: AI-supported biopsy image processing for accurate pathology diagnosis and stagingabstractThe Deep-in-Biopsies (DiB) platform supports diagnosing and staging diseases using patient biopsy imaging. This flexible service is designed for medical units to handle multiple organs and diseases. Specialists can train the system on demand using their selected images and annotations, which can be generated using an embedded annotation tool. The system proposes pathology findings to the expert for validation, and validated findings can be used for further training. Odysseas Tsakai, Panagiotis N. Smyrlis, Nikolaos S. Katertsidis, Alexandros T. Tzallas, Nikolaos Giannakeas, Markos G. Tsipouras |
BIBM | 5 |
| 2023 | Enhanced Alzheimer's disease and Frontotemporal Dementia EEG Detection: Combining lightGBM Gradient Boosting with Complexity FeaturesabstractAlzheimer's disease and Frontotemporal dementia are the two most reported dementia cases. They both are neurodegenerative disorders without cure while existing treatments only halt their progress. Thus, early detection is of crucial importance. In this work, we utilize electroencephalographic signals of AD and FTD patients and propose a classification pipeline to distinguish them from healthy signals. This pipeline consists of Independent Component Analysis as a preprocessing stage, the extraction of time, frequency and complexity features, feature elimination through importance ranking and finally classification through utilizing Gradient Boosting Decision Trees. The proposed methodology achieved 92.27% F1 score in the Dementia versus Control problem, 83.06% in the AD versus Control and 80.67% in the FTD versus Control. Andreas Miltiadous, Katerina D. Tzimourta, Vasileios Aspiotis, Theodora Afrantou, Markos G. Tsipouras, Nikolaos Giannakeas, Evripidis Glavas, Alexandros T. Tzallas |
CBMS | 6 |
| 2023 | Performance and early drop prediction for higher education students using machine learning
Vasileios Christou, Ioannis G. Tsoulos, Vasileios Loupas, Alexandros T. Tzallas, Christos Gogos, Petros S. Karvelis, Nikolaos Antoniadis, Evripidis Glavas, Nikolaos Giannakeas |
Expert Syst. Appl. | 9 |
| 2023 | Scalable Consensus Over Finite Capacities in Multiagent IoT EcosystemsabstractIn the real world, consensus achievement is an adaptive and evolutionary process. Tailor-made mechanisms are engaging in the light of disputes to resolve emerging contradictions between the atoms. Most of the dominant blockchain architectures tend to oversee this fact. They come integrated with rigid, overkilling consensus-achievement procedures, which, in many cases, are not necessary or significantly beneficial. They often raise overwhelming demands on the nodes and prohibit the deployment of fully distributed and peer blockchain operation in the IoT world. Still, for the IoT ecosystems and the metaverse to become self-sustainable and self-evolving, robust validity mechanisms must be embedded in the atomic scale. This work investigates the process of building and sustaining scalable consensus policies over the trivial atomic capacities of the IoT ecosystems. For this, we deploy the IoT microblockchain framework as an atomic consistency tier and we define a primary set of validity rules that every node can easily carry out. The initial concept relies on Gödel’s incompleteness theorems and K. Friston’s free energy principle and is investigated under the perspectives of graph and game theory. To study the dynamic behavior of the system, a competitive game among the nodes is run. The Proof of Existence (PoE) is utilized as a universal proofing case. Its feasibility is demonstrated, and its complexity is analyzed under various system considerations. The findings prove that finite-capacity atoms can collectively and efficiently support verifiable validity and scalable consensus in the evolutionary IoT ecosystems and the metaverse, even under conditions of high diversity, trivial capacity, and eventual consistency. Aristidis G. Anagnostakis, Charilaos Naxakis, Nikolaos Giannakeas, Markos G. Tsipouras, Alexandros T. Tzallas, Evripidis Glavas |
IEEE Internet Things J. | 3 |
| 2022 | Heterogeneous hybrid extreme learning machine for temperature sensor accuracy improvement
Vasileios Christou, Kyriakos Koritsoglou, Georgios Ntritsos, Georgios Tsoumanis, Markos G. Tsipouras, Nikolaos Giannakeas, Evripidis Glavas, Alexandros T. Tzallas |
Expert Syst. Appl. | 6 |
| 2021 | Machine Learning Algorithms and Statistical Approaches for Alzheimer's Disease Analysis Based on Resting-State EEG Recordings: A Systematic ReviewabstractAlzheimer's Disease (AD) is a neurodegenerative disorder and the most common type of dementia with a great prevalence in western countries. The diagnosis of AD and its progression is performed through a variety of clinical procedures including neuropsychological and physical examination, Electroencephalographic (EEG) recording, brain imaging and blood analysis. During the last decades, analysis of the electrophysiological dynamics in AD patients has gained great research interest, as an alternative and cost-effective approach. This paper summarizes recent publications focusing on (a) AD detection and (b) the correlation of quantitative EEG features with AD progression, as it is estimated by Mini Mental State Examination (MMSE) score. A total of 49 experimental studies published from 2009 until 2020, which apply machine learning algorithms on resting state EEG recordings from AD patients, are reviewed. Results of each experimental study are presented and compared. The majority of the studies focus on AD detection incorporating Support Vector Machines, while deep learning techniques have not yet been applied on large EEG datasets. Promising conclusions for future studies are presented. Katerina D. Tzimourta, Vasileios Christou, Alexandros T. Tzallas, Nikolaos Giannakeas, Loukas G. Astrakas, Pantelis Angelidis 0001, Dimitrios G. Tsalikakis, Markos G. Tsipouras |
Int. J. Neural Syst. | 4 |
| 2020 | Motor data analysis of Parkinson's disease patientsabstractIn this manuscript, a methodology for analysing motor signals from Parkinson's disease (PD) patients is presented. The signals are obtained from PD patients while wearing a glove device and sequentially performing standard motor tests. The signals are processed in order to detect the onset and offset from specific items (items 23-25) of the Unified Parkinson's Disease Rating Scale (UPDRS) and then the isolated signal parts are analysed in order to quantity the motor findings defined in UPDRS for these items, such as hesitation, movement amplitude and frequency, and rotation range. The obtained results indicate that the methodology can achieve accurate motor assessment (related to ground-truth UPDRS) for both “Off” and “On” stages. Vasiliki Fiska, Nikolaos Giannakeas, Nikolaos S. Katertsidis, Alexandros T. Tzallas, Konstantinos Kalafatakis, Markos G. Tsipouras |
BIBE | 2 |
| 2020 | Fetal Heart Beat detection based on Empirical Mode Decomposition, Signal Quality Indices and Correlation AnalysisabstractThe purpose of fetal monitoring during childbirth is the early recognition of any pathological conditions to guide a clinician in early intervention to avoid any complication in the health of the fetus. Non-Invasive Fetal Electrocardiography (NIFECG) represents an alternative fetal monitoring technique. The fetal ECG (fECG) derived from maternal thoracic and abdominal ECG recordings, provides an alternative to typical embryo monitoring means. In addition, it allows for long-term and ambulatory registrations that broaden the diagnostic capabilities for assessing the fetal health. However, in real situations, clear fECG is difficult to extract because it is usually overwhelmed by the dominant maternal ECG and other contaminated noise such as baseline wander and high-frequency interference. In this paper, a novel integrated adaptive methodology based on the combination of blind source separation, empirical mode decomposition, wavelet shrinkage denoising and correlation analysis, for the non-invasive extraction and processing of the FECG, is proposed. The methodology has been evaluated using both real and simulated recordings, and the obtained results indicate it efficiently. Theodoros Lampros, Konstantinos Kalafatakis, Ioannis G. Violaris, Nikolaos Giannakeas, Alexandros T. Tzallas, Markos G. Tsipouras |
BIBE | 4 |
| 2020 | Self-Adaptive Hybrid Extreme Learning Machine for Heterogeneous Neural NetworksabstractThis paper presents a hybrid algorithm for the creation of heterogeneous single layer neural networks (SLNNs). The proposed self-adaptive heterogeneous hybrid extreme learning machine (SA-He-HyELM) trains a series of SLNNs with different neuron types in the hidden layer utilizing the extreme learning machine (ELM) algorithm. These networks are evolved into heterogeneous networks (networks having different combinations of hidden neurons) with the help of a modified genetic algorithm (GA). The algorithm is able to handle two architecturally different neuron types: traditional low order (linear) units and higher order units with different transfer functions. The GA is fully self-adaptive and uses one novel hybrid crossover operator along with a self-adaptive mutation operator in order to retain ELM's simplicity and minimize the number of parameters need tuning. The experimental part of the current paper involves testing SA-He-HyELM with traditional ELM and other three ELM-based methods. The experimental part utilized a series of regression and classification experiments on relatively large datasets. In all cases the proposed method managed to get lower MSE or higher classification accuracy when compared to the aforementioned methods. Vasileios Christou, Georgios Ntritsos, Alexandros T. Tzallas, Markos G. Tsipouras, Nikolaos Giannakeas |
IJCNN | 5 |
| 2019 | Automated Assessment of Pain Intensity Based on EEG Signal AnalysisabstractObjective characterization of pain intensity is necessary under certain clinical conditions. The portable electroencephalogram (EEG) is a cost-effective assessment tool and lately, new methods using efficient analysis of related dynamic changes in brain activity in the EEG recordings proved that these can reflect the dynamic changes of pain intensity. In this paper, a novel method for automated assessment of pain intensity using EEG data is presented. EEG recordings from twenty-two (22) healthy volunteers are recorded with the Emotiv EPOC+ using the Cold Pressor Test (CPT) protocol. The relative power of each brain band's energy for each channel is extracted and the stochastic forest algorithm is employed for discrimination across five classes, depicting the pain intensity. Obtained results in terms of classification accuracy reached high levels (72.7%), which renders the proposed method suitable for automated pain detection and quantification of its intensity. Panagiotis A. Bonotis, Dimosthenis C. Tsouros, Panagiotis N. Smyrlis, Alexandros T. Tzallas, Nikolaos Giannakeas, Evripidis Glavas, Markos G. Tsipouras |
BIBE | 5 |
| 2019 | Hybrid extreme learning machine approach for heterogeneous neural networks
Vasileios Christou, Markos G. Tsipouras, Nikolaos Giannakeas, Alexandros T. Tzallas, Gavin Brown 0001 |
Neurocomputing | 3 |
| 2018 | Random Forests with Stochastic Induction of Decision TreesabstractIn this paper, a novel stochastic approach for the induction of the decision trees in a tree-structured ensemble classifier is presented. The proposed algorithm is based on a stochastic process to induct each decision tree, assigning a probability for the selection of the split attribute in every tree node, designed in order to create strong and independent trees. A selection of 33 well-known classification datasets have been employed for the evaluation of the proposed algorithm, obtaining high classification results, in terms of Classification Accuracy, Average Sensitivity and Average Precision. Furthermore, a comparative study with Random Forest, Random Subspace and C4.5 is performed. The obtained results indicate the importance of the proposed algorithm, since it achieved the highest overall results in all metrics. Markos G. Tsipouras, Dimosthenis C. Tsouros, Panagiotis N. Smyrlis, Nikolaos Giannakeas, Alexandros T. Tzallas |
ICTAI | 4 |
| 2018 | Assessing the Frailty of Older People using Bluetooth Beacons DataabstractSensor-based quantitative assessment of frailty in older adults usually requires expensive wearables or ambient sensors. However, low cost activity tracking systems can be effective in discriminating frailty characteristics. In this work, a system for assessment of the frailty of older people is presented, based on the analysis of data describing the daily in-house activity. More specifically, room-to-room movements are recorded using a set of Bluetooth beacons, located in fixed positions inside each room. A smartphone is used to locate the timestamps of room transitions, and these are used to calculate the time spent in each room, thus generating the time intervals signal. Then, several features depicting the in-house mobility are extracted from each signal and are evaluated, in terms of correlation with the subject's frailty status. Furthermore, the features are used to train a classifier for frailty assessment. Two approaches are evaluated, with different number of levels of frailty, and the results indicate that this procedure can lead to reliable older people frailty assessments, especially when two levels of frailty are considered. Markos G. Tsipouras, Nikolaos Giannakeas, Thomas I. Tegou, Ilias Kalamaras, Konstantinos Votis, Dimitrios Tzovaras |
WiMob | 2 |
| 2018 | Hybrid extreme learning machine approach for homogeneous neural networks
Vasileios Christou, Markos G. Tsipouras, Nikolaos Giannakeas, Alexandros T. Tzallas |
Neurocomputing | 3 |
| 2017 | Image Enhancement of Routine Biopsies: A Case for Liver Tissue DetectionabstractAnalysis of histopathological images covers a wide field of clinical practice in different pathological conditions. In many cases, biopsy images from different sources share similar characteristics. In this work, a method for image enhancement of biopsy images is proposed. During the first stage, the quality of the image is optimized, while in the second stage, a clustering technique is employed to separate the tissue from the background. For the evaluation of the method, Liver biopsies which have been extracted for the staging of Hepatitis C, are employed. The methodology has been tested using 19 liver biopsy images from patients who suffer from hepatic fibrosis and steatosis, obtaining detection Accuracy over 97% in pixel level. Nikolaos Giannakeas, Maria Tsiplakidou, Markos G. Tsipouras, Pinelopi Manousou, Roberta Forlano, Alexandros T. Tzallas |
BIBE | 1 |
| 2017 | Protein Structure Recognition by Means of Sequential Pattern MiningabstractIn this work, an innovative classification algorithmic technique through sequential pattern mining was developed to predict the secondary structure of proteins. A basic algorithm was selected for the extraction of the sequential patterns and another algorithm was developed which employs these patterns for protein structure prediction. In the matter of predicting protein structures and scoring sequential patterns, several methodologies has been implemented that theoretically and experimentally overcome the disadvantages of existing algorithms. Anna N. Ntagiou, Markos G. Tsipouras, Nikolaos Giannakeas, Alexandros T. Tzallas |
BIBE | 3 |
| 2017 | Rule Editor for ARDEN Syntax Generation towards a more Effective Self-Management of Asthma Disease PatientsabstractThe Decision Support tool of the myAirCoach platform is presented in this work. MyAirCoach is a web-based platform for personalized management of asthma patients. The Decision Support tool is used from medical experts to generate knowledge-based rules for asthma patients. The tool is a web-based application that includes a simple-to-use rule editor for generating medical rules in Arden Syntax, which is an HL7 standard. The logic of the rules in formulated in disjunctive normal form. Using the this tool, medical experts can generate rules and specify the set of rules that are applicable for alerting each patient, thus creating a personalized decision support system for asthma patients. Markos G. Tsipouras, Nikolaos Giannakeas, Stefanos Doumpoulakis, Antonis Voulgaridis, Dimitrios Kikidis, Konstantinos Votis, Dimitrios Tzovaras |
BIBE | 2 |
| 2017 | Measuring Steatosis in Liver Biopsies Using Machine Learning and Morphological ImagingabstractNon-Alcohol Liver Disease (NAFLD) is nowadays the most common liver disease in Western Countries. It is the chronic condition of fat expansion in liver, which is not associated with alcohol consumption. Quantitating steatosis in liver biopsies could provide objective measurement of the severity of the disease, instead of using semi-quantitative scoring systems. The current work, introduces an automated method for measuring steatosis in liver biopsies, using both machine learning and classical image processing techniques. Clustering is employed for tissue specimen detection, while an iterative morphological procedure is used for steatosis revealing. The method has been evaluated in a set of 20 liver biopsy images and the obtained results present ~1% mean percentage error. Nikolaos Giannakeas, Markos G. Tsipouras, Alexandros T. Tzallas, Maria G. Vavva, Maria Tsiplakidou, E. C. Karvounis, Roberta Forlano, Pinelopi Manousou |
CBMS | 1 |
| 2017 | Automated Collagen Proportional Area Extraction in Liver Biopsy Images Using a Novel Classification via Clustering AlgorithmabstractDiagnosis and staging of liver diseases are essential for the therapeutic efficacy of medication and treatment strategies. Measuring the Collagen Proportional Area (CPA) in liver biopsies recently becomes an effective tool for the assessment of fibrosis in liver tissues. State of the art image processing techniques are employed to analyze biopsy images, providing objective assessment of diseases severity. In current work a novel modification of K-means clustering is proposed for image segmentation of liver biopsies. More specifically, supervised restriction of centroids movement is utilized. In the first stage, a training set of images are employed to extract a hypercube for each class. Then, one centroid is initialized inside each hypercube and during the iterations of the clustering is allowed to move only inside the hypercube. For the evaluation of the proposed method 8 liver biopsy images are employed and classification results along with CPA values are computed for each image. Dimosthenis C. Tsouros, Panagiotis N. Smyrlis, Markos G. Tsipouras, Dimitrios G. Tsalikakis, Nikolaos Giannakeas, Alexandros T. Tzallas, Pinelopi Manousou |
CBMS | 5 |
| 2017 | EEG Classification and Short-Term Epilepsy Prognosis Using Brain Computer Interface SoftwareabstractThe recent advances of Brain Computer Interfaces (BCI) systems, can provide effective assistance for real time prognosis systems for patients who suffered from epileptic seizures. This paper presents an EEG classification strategy for short-term epilepsy prognosis, using software for Brain-Computer Interface (BCI) systems. A training scenario is presented, where significant features are extracted and a classification algorithm is trained. The training procedure extracts knowledge in terms of a classification model, which is employed in a real-time testing. For the training of the classification scenario a five-classes dataset of EEG signals is employed in which two-classes have been recorded extracranially and the rest three intracranially including one class with epileptic seizure activity and two classes with seizure-free signals. Promising quantitative results are reported. Alexandros T. Tzallas, Nikolaos Giannakeas, Kostantinos N. Zoulis, Markos G. Tsipouras, Evripidis Glavas, Katerina D. Tzimourta, Loukas G. Astrakas, Spiros Konitsiotis |
CBMS | 2 |
| 2017 | Wavelet Based Classification of Epileptic Seizures in EEG SignalsabstractEpilepsy is a chronic neurological disorder characterized by recurrent, sudden discharges of cerebral neurons, called seizures. Seizures are not always clearly defined and have extremely varied morphologies. Neurophysiologists are not always able to discriminate seizures, especially in long-term EEG datasets. Affecting 1% of the worlds population with 1/3 of the epileptic patients not corresponding to anti-epileptic medication, epilepsy is constantly under the microscope and systems for automated detection of seizures are thoroughly examined. In this paper, a method for automated detection of epileptic activity is presented. The Discrete Wavelet Transform (DWT) is used to decompose the EEG recordings in several subbands and five features are extracted from the wavelet coefficients creating a set of features. The extracted feature vector is used to train a Support Vector Machine (SVM) classifier. Five classification problems are addressed, reaching high levels of overall accuracy ranging from 87% to 100%. Katerina D. Tzimourta, Loukas G. Astrakas, Markos G. Tsipouras, Nikolaos Giannakeas, Alexandros T. Tzallas, Spiros Konitsiotis |
CBMS | 4 |
| 2008 | Intelligent patient profiling for diagnosis, staging and treatment selection in colon cancerabstractThe selection of a personalized treatment plan for a patient with cancer can be of critical importance for his health or even survival. A Decision Support Platform that can associate the patient clinical situation with the patient DNA Single Nucleotide Polymorphisms (SNPs) can provide the oncologist with a better understanding of the personalized conditions of every single patient. In this paper we present the MATCH platform which performs data integration between medicine and molecular biology, by developing a framework where, clinical and genomic features are appropriately combined in order to handle colon cancer diseases. The core of the platform is based on clustering techniques which provide profiles of patients with similar clinical features and genetic predispositions to cancer. The patients which share the same profile should probably have similar treatment plan and follow up. Through the integration of the clinical and genetic data of a patient, real time conclusions can be drawn for his early diagnosis, staging and more effective colon cancer treatment. Intelligent components are designed and developed which identify single nucleotide polymorphisms (SNPs) from the gene sequences and combine them with the clinical situation of the patient. The produced clinico-genomic profiles are used as a decision support tool for newly sequenced patients. Yorgos Goletsis, Themis P. Exarchos, Nikolaos Giannakeas, Dimitrios I. Fotiadis |
BIBE | 3 |
| 2008 | Point-of-care monitoring and diagnostics for autoimmune diseasesabstractIn this paper we present the POCEMON platform, a platform aiming to the early prognosis and diagnosis of autoimmune diseases at any point of care, even the primary. The objective of the POCEMON platform is the development of a diagnostic lab-on-chip device based on genomic microarrays of HLA-typing. The POCEMON is going to advance and promote the primary health care across Europe by supporting a) point-of-care diagnostics, b) monitoring of immune system status and c) management of the chronic multiple sclerosis (MS) and rheumatoid arthritis (RA) autoimmune diseases. The platform combines high-end Information and Communication Technologies based on microfluidics, microelectronics, microarrays and intelligent diagnosis algorithms. Fanis G. Kalatzis, Themis P. Exarchos, Nikolaos Giannakeas, Sofia Markoula, Elisavet Hatzi, Panagiotis Rizos, Ioannis Georgiou, Dimitrios I. Fotiadis |
BIBE | 3 |